The rocker, who has suffered poor health in recent years, was admitted to a hospital in San Francisco, California after suffering a heart attack earlier this week (beg25Jan16) and he passed away on Thursday due to multiple organ failure and septic shock.

He was best known for co-founding psychedelic rock band Jefferson Airplane in the 1960s, as well as spin-off group Jefferson Starship, and members of Jim Morrison's The Doors, who also rose to fame in California in the '60s, have paid tribute to Kantner.

"Our condolences go out to the friends, family and fans of Paul Kantner of Jefferson Airplane on the news of his passing," the musicians write in a statement posted on the band's Facebook.com page. "Music would not be the same without the sounds of The Doors and Jefferson Airplane, which both contributed so heavily to the signature sound of the 60s and 70s. They often shared the same bill."

Slick, who worked with Paul in Jefferson Airplane and Jefferson Starship, has also mourned the loss, sharing a picture of her pal on Facebook and adding, "Rest in peace my friend. Love Grace."